Yeast hydrolyzate oral ingesta for animals

ABSTRACT

The palatability of oral ingesta, such as animal food or orally administered animal medicaments is improved by combining such ingesta with hydrolyzates of yeast from the genera ascomycetous yeasts or asporogenous yeasts. Oral ingesta such as an animal medicament or animal food is combined with either hydrolyzates of Torulopsis utilis or Saccharomyces cerevisiae.

BRIEF SUMMARY OF THE INVENTION

The present invention is a Continuation in Part of my co-pending United States patent applications Ser. No. 448,208 filed Mar. 5, 1974 now U.S. Pat. No. 3,997,675 and Ser. No. 463,314 filed Apr. 23, 1974, now U.S. Pat. No. 4,000,319 and Ser. No. 473,347 filed May 28, 1974, now abandoned.

The palatability of oral ingesta such as an animal food or orally administered animal medicaments is improved by combining such food with hydrolyzates of the yeast from the genera ascomycetous yeast or asporogenous yeast. The hydrolyzates of the yeast-like genera belonging to the order Ustilaginales (in the Basidiomycetes) and the yeast-like genera belong to the family Sporobolomycetaceae are also within the broad scope of the invention. In one embodiment, the palatability of oral ingesta such as animal food or animal medicaments such as dog or cat food or orally administered medicaments for cats or dogs is improved by coating such food with hydrolyzates of yeasts comprising either Torulopsis, Candida, or Saccharomvces. An outstanding feature of the invention is that the hydrolyzates of yeasts suitable for improving the palatability of such ingesta are high in essential B vitamins and proteins. The ingest combined with yeasts hydrolyzates according to the invention may also be used in the dry state, the palatability not being dependent on the addition to or incorporation of water or liquid to improve flavor or release flavor ingredients. Water or other liquids however may be employed, if desired. The examples describe the results obtained by combining an animal medicament and a comestible suitable for use as animal food with hydrolyzates of Torulopsis utilis and Saccharomvces cerevisiae.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to oral ingesta such as animal food or orally administered animal medicaments especially such animal food or medicament of improved palatability. More specifically, the present invention relates to animal food or orally administered animal medicaments such as dog food or medicaments and cat food or medicaments having improved palatability.

Problems have been encountered with the prior art canned, dry and moist animal food in that some canned pet food although having good palatability, was low in nutritional value because anywhere from 60-70% of the canned food comprised water and further the ingredients of such canned foods were qualitatively lacking in the nutritive food values essential for sustaining animal health.

On the other hand, commercially-available dry animal food generally has low to poor palatability but is exceptionally high in nutritive value. This dry animal food is supplied as kibs which are spheres, cylinders or cubes of anywhere from about 1/8 inch to about 1/4 inch maximum dimension. The lack of palatability or poor palatability affects animal nutrition in that the animal fed with such food would not consume enough of the food to maintain proper health. Consequently several attempts have been made in the prior art to improve the palatability of dry animal food kibs as set forth in U.S. Pat. No. 3,119,691 Ludington et al. in which the kib has applied to it a coating which forms a gravy containing mixture upon addition of water.

One of the difficulties with the prior art dry animal food kibs having a coating which forms a gravy containing mixture on the addition of water was that after the kib has been treated with water the kib would tend to soften after standing about 12 hours, the animal would no longer be interested in the food and, consequently, the food had to be thrown out. Additionally, if the kibs were wet and allowed to stand for a sufficient length of time, the likelihood of spoilage would increase thereby negating the long storage properties of the dry kibs. This would be a particular disadvantage if the animal had to be left food for one or more days. Furthermore, the user of the food had to go to the difficulty of mixing up the dry animal food kibs with water prior to use which involved an extra step in the preparation of the animal food which detracts from the ready-to-use characteristics of dry food.

The prior art also teaches improvement in the palatability of dry animal food kibs by the addition of liquid beef extract such as beef broth or fish scrap. It has been observed, however, that even with the addition of liquid beef extracts, such as beef broth or fish scrap, to standard commercially-prepared dry animal food kibs, the resultant dry animal food kib does not have sufficient palatability to induce an animal to eat sufficient amounts of the animal food to maintain proper nutrition.

One of the other problems encountered in the prior art was the difficulty in formulating substantially farinaceous animal food such as those based on grains that include rye, wheat, oats, barley and corn to be palatable to carnivores. Admixing farinaceous materials with meat, meat by-products, and meat meal as additives and extracts thereof as flavorants were generally the method employed in the prior art to improve the palatability of farinaceous materials however this was generally expensive and of limited success. Similar problems were encountered in the prior art with formulating vegetable protein animal food to be palatable for carnivores. Again vegetable proteins admixed with meat, meat by-products, meat meal and extracts thereof was a method for obviating the problems as employed in U.S. Pat. No. 3,202,514 Burgess et al. with the attendant aforementioned drawbacks of high cost and limited success in avoiding the problem.

It has also been observed that moist animal food as described in U.S. Pat. No. 3,202,514 Burgess et al. although having improved palatability over commercially-available dry animal food, the palatability of this moist animal food is not at an optimum and decreases after a period of about two days after unpackaging.

An additional problem with the prior art flavorants for animal food is that they are extremely low in any nutritive value.

The administration of oral medicaments to animals such as cats or dogs is also difficult because most medicaments have a taste offensive to the animal. This may be partially obviated by mixing the medicament with the animal food; however, if the animal is suffering from a loss of appetite or diminished appetite as one symptom of a disease or disorder, the food will not be fully consumed and consequently less than the recommended dosage will be taken. In some instances, this can be obviated by resorting to injectable medicaments as in the case of penicillin which may be administered orally as in the case of Pen-V and Ampicillin or may be injected such as Pen G of semi-synthetic penicillin such as Carbenicillin. Injectables present some difficulty in use that trained personnel are required for their administration, some discomfort is suffered by the animal and administration requires special equipment, i.e., a hypodermic needle and syringe. Additionally, not all medicaments are available as injectables or in oral dosage units as are the penicillin. It would therefore be desirable to improve the palatability of orally administered animal medicaments to assure full dosage is received by the animal and to avoid the other aforementioned difficulties associated with the non-oral administration of such medicaments.

It is therefore an object of the present invention to overcome these and other difficulties of the prior art and especially to provide a process for improving the palatability of oral ingesta such as animal food and orally administered medicaments for animals as well as to provide an article of manufacture comprising ingesta such as animal food and orally administered medicaments for animals having improved palatability.

It is a further object of the present invention to provide a process for improving the palatability of such ingesta and to provide an article of manufacture comprising such ingesta having improved palatability which does not require the addition of water or any other liquid to obtain such improved palatability.

It is a further object of the present invention to provide as an article of manufacture ingesta such as animal food which are substantially farinaceous compositions or vegetable protein compositions or mixtures thereof that are palatable to carnivores. It is also an object of the invention to provide a method of making a substantially farinaceous comestible or vegetable protein ingesta or mixtures thereof palatable to a carnivore without the use of meat, meat by-products, meat meal or extracts thereof.

It is a further object of this invention to improve the palatability of ingesta such as moist animal food of from about 15 to about 30% by weight moisture; meat or meat by-products or meat meal or mixtures thereof; vegetable protein and optionally from about 15% to about 30% by weight of sugar.

It is also an object of the present invention to provide a process for improving the palatability of such ingesta and to provide an article of manufacture comprising such ingesta having improved palatability by means of a product that is high in B vitamins and amino acids.

These and other objects have been achieved by the present invention in which an article of manufacture is provided comprising ingesta such as aniaml food and orally administered medicaments for animals which has been combined with a hydrolyzate of yeast. Throughout the specification, the ingesta of the present invention is described as being combined with a hydrolyzate of yeast by which it is meant that such hydrolyzate of yeast may be employed as a surface coating on such ingesta or in admixture with such ingesta or both. Hydrolyzates of Yeasts from either the group ascomycetous or asporogenous have been found to be effective in this regard. The hydrolyzates of yeast-like genera belonging to the order Ustilaginales (in the Basidiomycetes) and the yeast-like genera belong to the family Sporobolomycetes) and the yeast-like genera belong to the family Sporobolomycetaceae are also within the broad scope of the invention. The yeasts that are hydrolyzed and employed in accord with the present invention are further identified in the publication. The Yeasts, A Taxonomic Study, edited by J. Lodder, 1970.

The various genera of yeasts within the group ascomycetous which can be employed according to the present invention include Endomycopsis, Kluyveromyces, Saccharomyces, Saccharomycodes, Saccharomycopsis and Schizosaccharomyces.

The various genera of asporogenous yeasts that can be employed according to the present invention especially asporogenous yeast not belonging to the Sporobolomycetaceae include Candida, Oosporidium and Torulopsis.

The species of yeast in the group asporogenous that can be employed to advantage according to the present invention comprise Torulopsis utilis (Candida utilis) and Candida arborea, Oospora lactis (Oidium lactis, Endomvces lactis, Geotrichum candidum).

Because of the commercial usage the term "Torula yeast" or "torula yeast" is employed to designate the species Torula utilis, Torulopsis utilis and Candida utilis, the latter three being treated as synonyms in The Yeasts, supra. The genera Candida and Torulopsis are maintained as separate genera in The Yeasts, supra for the reasons stated at pages 894-897 thereof because of reclassification into natural taxa is considered "inadvisable since it would make necessary the provisory renaming of a great number of species. This would inevitably lead to confusion and justified irritation among the increasing number of workers in various fields who use or encounter yeast of this group."

The various species within the group ascomycetous which are also employed to advantage according to the present invention comprise Saccharomyces cerevisiae, Saccharomyces cerevisiae variety ellipsoidus, Saccharomyces carlsbergensis and Saccharomyces fragilis (Kluyveromyces fragilis).

The genera of yeasts preferred in accord with the present invention comprise Torulopsis, Candida and Saccharomyces.

Commercially-available dried yeast which are used according to the present invention includes either primary dried yeast or secondary yeasts which may be classified as follows:

1. Primary dried yeast -- Saccharomyces cerevisiae

2. Primary dried torula yeast -- Torulopsis utilis (Candida utilis)

3. Secondary yeast, brewer's dried yeast -- Saccharomyces cerevisiae, Saccharomyces carlsbergensis

The composition of commercially-available dried primary yeast is given in the 11th Edition of The National Formulary, pages 395-396 and is as follows:

    ______________________________________                                         protein (N × 6.25)                                                                           minimum    45%                                             thiamine hydrochloride (vitamin B.sub.1)                                                           minimum    120    μg/g                                  riboflavin (vitamin B.sub.2)                                                                       minimum    40     μg/g                                  nicotinic acid      minimum    300    μg/g                                  fermenting power    inactive                                                   fillers             none                                                       total bacterial count                                                                              maximum    7500   μg/g                                  mold count          maximum    50     μg/g                                  moisture            maximum    7%                                              ash                 maximum    8%                                              ______________________________________                                    

Primary dried yeasts which are marketed for food usage have the following analysis which is considered typical:

    ______________________________________                                         moisture     5.0%      calcium      0.3%                                       protein      50.0%     phosphorous  2.4%                                       fat (ether ext.)                                                                            1.2%      potassium    2.6%                                       total lipids 5.5%      magnesium    0.5%                                       carbohydrates                                                                               31.5%     sodium       0.4%                                       ash          8.0%                                                              ______________________________________                                    

The amino acid content of primary dried yeast is approximately as follows as expressed as a percent of dried proteins:

    ______________________________________                                         alanine      9.0%      lysine       8.2%                                       arginine     5.0%      methionine   2.5%                                       aspartic acid                                                                               4.0%      phenylalinine                                                                               4.5%                                       cystine      1.6%      proline      2.5%                                       glutamic acid                                                                               13.5%     threonine    5.5%                                       glycine      0.6%       (and serine)                                           histidine    4.0%      tryptophan   1.2%                                       hydroxyproline                                                                              4.5%      tyrosine     5.0%                                       isoleucine   5.5%      valine       5.5%                                       leucine      8.0%      others       9.4%                                       ______________________________________                                    

All essential amino acids are present as can be seen from the above analysis. The vitamin contents of the various products are as follows in μg/g):

    ______________________________________                                         thiamine              up to 10,000.0                                           riboflavin            up to 12,000.0                                           niacin                up to 30,000.0                                           pyridoxine            15.0                                                     pantothenic acid      110.0                                                    biotin                2.5                                                      inositol              4,000.0                                                  choline               4,000.0                                                  p-aminobenzoic acid   13.0                                                     folic acid            11.0                                                     ______________________________________                                    

Secondary yeasts are those yeasts which are obtained upon the completion of brewery operation or production of alcohol from molasses and rum production, and is then subject to a purification after which it is dried to about 90% solids content and marketed as dried distiller's or dried brewer's yeast.

Primary and secondary brewer's dried yeast have approximately the same analyses.

Secondary brewer's dried yeast analyzes typically as follows:

    ______________________________________                                         protein      50.0%     zinc       38.7 ppm                                     fat          1.5%      salmonella negative                                     fiber        1.5%      coliform                                                ash          7.0%      bacteria   negative                                     moisture     6.0%      thiamine   56.6 mg/lb                                   nitrogen-free          riboflavin 16.0 mg/lb                                   extract      34.0%     niacin     225.5 mg/lb                                  calcium      0.12%     pantothenic                                             phosphorous  1.50%      acid      55.2 mg/lb                                   potassium    0.86%     pyridoxine 22.6 mg/lb                                   iron         0.02%     choline    2200.0 mg/lb                                 copper        35 ppm   betaine    544.0 mg/lb                                  manganese    5.3 ppm   biotin     0.5 mg/lb                                    cobalt       1.5 ppm   folic acid 22.2 mg/lb                                                          inositol   2265.0 mg/lb                                 ______________________________________                                    

Other yeast which are suitable for the purposes of the present invention comprise vitamin enriched yeasts which are manufactured by the addition of vitamins such as vitamins B1, B2 and B6 to the broth in which the yeast is grown and from which the yeast will subsequently absorb the vitamins. One of the outstanding features of the yeast used in accord with the present invention is they synthesize vitamin B1 in large quantities during production by coupling thiazole and pyrimidine when these compounds are added to the medium in which the yeast is grown. Yeast which are made by the addition of thiazole and pyrimidine and vitamin-enriched yeasts manufactured according to U.S. Pat. No. 2,262,635 Schultz, et al., U.S. Pat. No. 2,359,521 Harrison and U.S. Pat. No. 2,328,025 Mead et al. are also included within the scope of the present invention. Hydrolyzates including autolyzates of the foregoing yeasts are used according to the present invention and are prepared either by hydrolyzing such yeasts in a dilute aqueous hydrochloric acid solution or by an aqueous bacterial hydrolysis both of which are known in the art. The hydrolyzate thus obtained is dried and concentrated and employed in the same manner as the yeasts described herein. Any mixture of yeasts and/or hydrolyzates including autolyzates may also be employed according to the invention.

The farinaceous ingesta of the present invention may be made from any of the more common grains, such as corn meal, red dog flour, wheat germ, rye flour, wheat flour, oats, barley, and the like, and any combination thereof.

The farinaceous ingesta utilizing the foregoing common grains or farinaceous materials may be prepared by methods well known in the baking art. The grains are ground into a flour-like consistency to which is added a liquid a shortening and, optionally, a leavening agent, such as baker's yeast or baking powder, and the mixture then baked at a suitable temperature for a fixed period of time. In one embodiment of the present invention, the farinaceous ingesta prepared with a leavening agent is shaped into a crouton-like configuration having dimensions of approximately 174 inch square dried at 110° F. for 2 hours and subsequently coated with the yeast of the present invention.

The ingesta of the present invention may also be made from vegetable protein materials which comprises oil seeds and legumes as well as the oil expressed or extracted meals and cakes and protein isolates thereof recovered by acid or alkali digestion and precipitation. Vegetable protein materials in this respect comprise soy beans, soy bean meal, soy bean powder, cotton seed meal, peanuts, peanut meal and the like and mixtures thereof.

The vegetable protein material may be used by itself. By way of example soy powder is pelletized by compression in a press into a 1/4 inch diameter by 1/8 inch thickness round pellet and these pellets in turn are coated with the aforementioned yeast or 30% by weight of such yeast is admixed with the soy powder prior to pelletizing.

Mixtures of the farinaceous materials and protein materials, especially vegetable protein materials may be effected for example by substituting approximately 10% by weight of the grain flour previously described with soy powder and/or 10% by weight of yeast and the baked goods prepared with this substitution. This combination of farinaceous material with the vegetable protein material may also be coated with the yeast previously described.

The moist animal food which is also combined with the yeast in accord with the present invention is described in U.S. Pat. No. 3,202,514 Burgess et al. such moist animal food generally comprising from about 15 to about 30% by weight of moisture; from about 15 to about 30% by weight of sugar, meat or meat by-products or meat meal or mixtures thereof as meat protein material; and vegetable protein material as described previously, all of these terms being further described in U.S. Pat. No. 3,202,514 Burgess et al. along with other components employed in such moist animal food and the method for its manufacture.

The ingesta of the invention comprising animal food are thus prepared from farinaceous materials, or proteinaceous materials or mixtures of farinaceous and proteinaceous materials. Where the ingesta comprises mixtures of farinaceous and proteinaceous materials, anywhere from about 2% to about 98% by weight of farinaceous material, especially from about 5% to about 80% by weight of farinaceous material is employed, the balance comprising proteinaceous material.

The proteinaceous material, whether employed by itself or in combination with the farinaceous material may be vegetable protein or meat protein or mixtures of both vegetable protein and meat protein. Where mixtures comprising vegetable protein and meat protein are employed, the vegetable protein comprises anywhere from about 2% to about 95% by weight of the mixture and especially from about 5% to about 85% by weight of the mixture the balance comprising meat protein.

Since other ingredients may be used in the manufacture of the ingesta or are present therein such as water the farinaceous and/or proteinaceous materials will constitute anywhere from about 95% to about 5% by weight, especially from about 95% to about 60% by weight of the ingesta.

The ingesta of the invention may be dry by which it is meant it may contain anywhere from about 5% to about 12% by weight of water based on the ingesta; or it may be moist by which it is meant it may contain anywhere from above about 12% to about 40% by weight of water based on the ingesta; or wet at > 40% water.

The oral medicaments which may be used in combination with the yeast according to the invention comprise those compositions and/or compounds in the Physician's Desk Reference, 29th Ed. (1974). The oral medicaments comprise inter alia compounds and/or compositions generally known as amebicides and trichomonacides, analgesics, anorexics, antiarthritics, antibacterials and antibiotics, anticoagulants, anticonvulsants, anti-depressants, antihistamines, antineoplastics, anti-Parkinsonism drugs, antipyretics, antipasmodics and anticholinergics, antiviral agents, ataractics, cardiovascular preparations, contraceptives, diuretics, fertility agent, hematinics, hormones, laxatives, parasympathetic agents and parasympathomimetics, psychostimulants, sedatives, sympathomimetics and combinations and thyroid preparations. Compounds and/or compositions within the aforementioned classes include inter alia the following generic materials; methamphetamine, methcyclothiazide cephalexmin, cephaloglycin, cloxacillin, phenoxyethyl penicillin, erythromycin, pargyline, ephedrine, codeine, methycyclothiazide, metharbital, deserpidine, pentobarbital, isoproterenol, piperazine, estrone, hydrochlorothiazide, ethchlorvynol, chlorazepate, sulfamethizole, phenazopyridine, oxytetracycline, pentaerythritol tetranitrate, diethylstilbestrol, 1-hyoscyamine, ethaverine, pentylenetetrazol, griseofulvin, ampicillin, phendimetrazine, meprobamate, conjugated estrogens, testosterone, pralidoxime, dicloxacillin, isoniazid, methanamine mandelate, phenacetin, aspirin, caffeine, hydrocodone bitartrate, oxacillin, phentermine, bisacodyl NF, phenmetrazine, ephedrine, glyceryl guaiacolate, phenobarbital, theophylline, sulfonamide, phenoxymethyl penicillin, kanamycin, tetracycline, hetacillin, metampicillin, aluminum glycinate, acetaminophen, salicylamide, methyltestosterone, bephenium hydroxynaphthoate, erythrityl tetranitrate, procyclidine, digoxin, cyclizine trimethoprim, sulfamethoxazole, benzyl penicillin, papaverine, hydralazine, allobarbital, acetaminophen, methandrostenolone, dimethindene, xylometazoline, tolazoline, tripenalennamine, reserpine, adiphenine, ethinamate, belladonna, piperacetazine, rifampin, warfarin, promethazine, sulfinpyrazone, phenylbutazone, oxyphenbutazone, carbamazepine, imipramine, furosemide, glyceryl trinitrate, isoproterenol, bromisovalum, pentylenetetrazol, isometheptene, oxyphenonium bromide, amantadine, lithium carbonate, butyrophenone, hydroxyzines, chorionic gonadotropin, menotropins, cyanocobalamin, dipyridamole, casanthranol, dioctyl sodium sulfosuccinate, methylphenidate, thyroxine, amphetamine, chlordiazepoxide, diazepam and sulfisoxazole.

The ingesta article of manufacture may be in the shape of a kib which is a sphere, cylinder or cube or other three dimensional shape having a maximum dimension of from about 1/8 inch to about 3/4 inch. The article of manufacture may also be biscuit shaped, wafer shaped or any shape commonly used for animal food or orally-administered animal medicaments. Biscuits may be anywhere from about 1/2 inch to 2 inches in diameter and have a thickness of about 5% to about 50% of the diameter. Wafers may be anywhere from about 1/2 inch to about 6 inches in length, about 1/2 inch to about 3 inches in width and have a thickness anywhere from about 5% to about 50% of the width. The wafers may also be bone shaped. The ingesta may also be prepared as a continuous cylindrical, triangular, rectangular etc. extrudate of about 1/4 inch in diameter.

The yeast hydrolyzate when combined with the ingesta as a coating may be applied to all sides or only one side or any combination of sides of the ingesta. The coating may also be applied as stripes on the side of the ingesta or what will be defined herein as flavor channels which are grooves having a depth of from about 1% to about 20% of the maximum thickness of the ingesta and are filled with the yeast coating. A continuous coating of yeast hydrolyzate or flavor channels may be applied by continuous coextrusion of the ingesta and yeast hydrolyzate through an extrusion die.

The ingesta such as animal food or orally-administered animal medicaments are combined with greater than about 2% by weight or anywhere from about 2% to about 99% by weight of yeast hydrolyzate either as a coating on the surface or in the flavor channels or in admixture with such ingesta where the aforesaid weight percent of yeast hydrolyzate is based on dry yeast, i.e., yeast having from about 3 to about 10% by weight of water. In a further embodiment of the ingesta of the invention have greater than about 5% and especially greater than about 7% or from about 5% to about 99% especially from about 7% to about 99% by weight of such yeast hydrolyzate combined therewith as an admixture or coating.

Where the ingesta of the invention comprises orally-administered medicaments, in addition to the foregoing ranges the yeast hydrolyzate may also be combined with such medicament in an even lesser amount such as, for example, in an amount greater than about 0.5%, such as anywhere from about 0.5% to about 99% by weight, the lower concentrations being especially effective when applied as a coating on such medicament.

The prior art discloses that yeast may be employed in animal food in concentrations up to about 0.5% as a B vitamin supplement; however, when yeast is used in admixture with animal food in such low concentrations it has no effect on improving the palatability of the animal food. Applicant has established by experiments that such animal food whether dry animal food or moist animal food described in U.S. Pat. Nos. 3,119,691 Ludington et al. and 3,202,514 Burgess et al. either have minimal palatability as dry animal food or lose palatability as in the case of moist animal food, but such palatability can be greatly enhanced by the use of greater than 0.5% by weight of yeast hydrolyzate as a coating on such animal food.

By applying yeast hydrolyzate as a surface coating to animal food or orally-administered medicaments in the ranges according to this invention even though a very small amount of yeast hydrolyzate may be employed in terms of the weight percent of yeast hydrolyzate in relation to the weight of the ingesta it is possible to obtain a substantially 100% yeast hydrolyzate concentration on the surface of the ingesta and the yeast is able to function in the manner discovered according to the present invention, i.e., as a compound that markedly improves palatability. When the yeast hydrolyzate is employed in admixtures with the ingesta, palatability will be reduced by virtue of the dilution effect of the ingesta on the yeast hydrolyzate. Consequently, slightly higher concentrations of the yeast hydrolyzate are preferred when it is combined with ingesta as an admixture.

By experimentation easily accomplished by a person with ordinary skill in the art, a minimum concentration of yeast hydrolyzate within the aforementioned ranges can be ascertained which will improve palatability and, accordingly, the aforementioned ranges of concentrations of yeast hydrolyzate in combination with the ingesta represent the numerical parameters for the use of yeast hydrolyzate as a compound to improve the palatability of oral ingesta. The yeast hydrolyzate is therefore used in combination with the ingesta in an amount sufficient to enhance the palatability and is readily distinguished from the prior art where yeast has been employed as an additive in such small amounts that no palatability improvement has been obtained because of the dilution factor which masked or hid the taste-enhancing qualities of the yeast.

Although the yeast hydrolyzate in one embodiment is combined with the ingesta by itself the yeast hydrolyzate may also be mixed with a binder, such as fat, e.g., tallow fat, or other edible binders known in the food art such as, starch binders, pre-cooked potato flour, pre-gelatinized starch, pre-gelatinized corn flour or the equivalent thereof, such as polymerized alkylene oxides, e.g. ethylene oxide, carrgeenins, alginates, locust bean gum, gum karaya, gum tragacanth and guar gum. Carboxymethyl cellulose may also be employed in this regard. When the yeast is employed in combination with a binder anywhere from about 5% to about 95% by weight, especially from about 20% to about 80% by weight of yeast to binder may be employed.

The yeast hydrolyzate or yeast hydrolyzate and binder may be combined with the ingesta by applying such yeast hydrolyzate as a coating to animal food by first moistening the surface of the animal food to convert the farinaceous material and/or proteinaceous material at the surface into a semi-moist tacky adhesive substrate onto which the dry yeast hydrolyzate or yeast hydrolyzate and binder may be applied after which the food thus coated may be dried so that the overall moisture content will be within any parameters desired. The yeast hydrolyzate and binder may also be applied to the surface of ingesta as a coating or admixed with the ingesta.

Since the yeast hydrolyzate with or without a binder of the present invention may provide a suitable substrate for the growth of mold or bacteria especially when used in combination with moist animal food, anti-mycotic and/or anti-bacterial agents may be optionally employed in combination with the yeast hydrolyzate or yeast hydrolyzate and binders to inhibit such development of mold and bacteria. Standard anti-mycotic and/or anti-bacterial agents known in the art may be employed each in amounts from 0.1% to about 2.5% by weight of the yeast although amounts as low as 50 p.p.m. may be used.

By way of example, anti-mycotic agents employed in this aspect of the invention include propylene glycol, diethyl pyrocarbonate, proprionic acid, sodium and calcium proprionate, benzoic acid, sodium benzoates, sorbic acid, potassium and calcium sorbate, menadione sodium bisulfite (vitamin K). Vitamin K is especially preferred in this respect. Art-known Bacteriostatic compounds may also be employed in the yeast such as acidulants, sugars, sodium chloride, and where high moisture binders or ingesta are employed, sorbitol, propylene glycol and other art-known equivalents that provide protection due to the osmotic pressure effect of such additive. These anti-mycotic agents and/or antibacterial agents or any combination thereof may be incorporated into the ingesta as well in an amount from about 0.1 to about 2.5% by weight of the ingesta and in some instances in amounts as low as 50 p.p.m.

The following examples are illustrative.

EXAMPLE 1

Upon presenting a common house cat a two ounce portion of croutons coated with 12% by weight of primary dried torula yeast hydrolyzate the coated croutons were immediately consumed by the animal. Prior to presenting the coated croutons, the animal was regularly fed so that it was not unduly hungry when given the coated croutons, i.e., an ordinary fooed regimen was maintained to assure that the animal was not excessively hungry when presented with the coated croutons. The same results were obtained with the croutons coated with primary brewer's dried yeast hydrolyzate, i.e., Saccharomyces cerevisiae.

EXAMPLE 2

A medicament was prepared for oral administration to be used in the control of round worms (toxascaris leonina) by admixing 0.25 oz. primary dried yeast Saccharomyces cerevisiae hydrolyzate with 0.0125 oz. of piperizine adipate. The medicament thus prepared was presented to a common house cat and it was immediately consumed. Piperazine adipate was administered again to the animal in 30 days by preparing a medicament as described in this example however using 0.25 oz. primary dried torula yeast Torulopsis utilis and such medicament was immediately consumed.

EXAMPLE 3

Commercially prepared dry cat food kibs were coated with 10% by weight of primary dried torula yeast, Torulopsis utilis hydrolyzate in one instance and in another instance with 10% by weight of primary dried yeast, Saccharomyces cerevisiae hydrolyzate, the weight percent of the coating in both instances being based on the weight of the dry cat food kibs. The yeast hydrolyzate employed in each instance had a moisture content of about 8% by weight.

It can be seen by employing the article of manufacture of the present invention that ingesta such as animal food can be prepared which has improved palatability and additionally the compound for enhancing the palatability of the ingesta such as an animal food is high in essential B vitamins as well as proteins. It is unexpected that a compound which is high in nutritive value also imparts improved palatability to animal ingesta. It is also unexpected that improved palatability for animal ingesta employed for the nutrition or medication of dogs or cats is obtained with a non-meat source such as the hydrolyzates of yeasts employed according to the present invention. It is even more unexpected that a non-meat compound such as the hydrolyzates of yeasts of the present invention can be combined with a non-meat ingesta and the ingesta thus obtained would be eaten by a carnivore as illustrated in the Examples. According to the prior art methods, meat, meat extracts, and the like were employed such as beef, beef broth or other beef extracts and fish scrap or fish extracts in order to improve the palatability of carnivore ingesta. It is also unexpected that a non-meat product of the present invention would improve the palatability of a meat based animal food for a carnivore as illustrated.

Various ranges have been employed throughout the specification to describe the various parameters of the invention however it is intended that where a range of properties is given that this range is to include any range falling within the range as well as any individual value within the range. By way of example and not limitation, the hydrolyzate yeast is described in one instance as from about 0.5% to about 99% by weight of the ingesta and a narrower range such as about 1% to about 99%, about 2% to about 99%, about 5% to about 80% by weight as well as any single value within the range such as 0.9, 3, 7.5, 12, 15% and the like are intended to be included within this range. As a further example, the moisture content of the yeast hydrolyzate employed is given as anywhere from about 5% to about 10% by weight and again the range is intended to include a narrower range within the range such as from about 6 to about 8% and any value falling within the range such as 7%, 9% and the like. This definition of the ranges of values is also to include the ratio of yeast hydrolyzate to binder if the binder is optionally employed, anti-mycotic and anti-bacterial agents as well as every other value given in the specification as a parameter or a set of parameters for practicing the invention set forth herein.

Although the invention has been described by reference to some preferred embodiments it is not intended that the novel article of manufacture and the method for making the same be limited thereby but that certain modifications are intended to be included within the broad scope and spirit of the preceding disclosure and the following claims. 

What is claimed is:
 1. A method for improving the palatability of oral ingesta for cats selected from a member of the group consisting of cat food and cat medicaments comprising combining said ingesta with yeast hydrolyzates in an amount sufficient to impart improved palatability to said ingesta, said yeast hydrolyzates being selected from a member of the group consisting of hydrolyzates of ascomycetous yeasts and asporogenous yeasts and feeding to said cat said oral ingesta combined with said yeast hydrolyzate.
 2. The method of claim 1 where said yeast hydrolyzate is selected from a member of the group consisting of the hydrolyzates of the genera Endomycopsis, Kluyveromyces, Saccharomyces, Saccharomycodes, Saccharomycopsis, Schizosaccharomyces, Candida, Cospiridium and Torulopsis.
 3. The method of claim 1 where said yeast hydrolyzate comprises Torulopsis hydrolyzate.
 4. The method of claim 1 wherein said yeast hydrolyzate comprises Candida hydrolyzate.
 5. The method of claim 1 where said yeast hydrolyzate comprises Saccharomyces hydrolyzate.
 6. The method of claim 3 where said yeast hydrolyzate comprises Torulopsis utilis hydrolyzate.
 7. The method of claim 5 where said yeast hydrolyzate comprises Saccharomyces cerevisiae hydrolyzate.
 8. The method of claim 2 where said ingesta comprises animal food.
 9. The method of claim 2 where said ingesta comprises an oral medicament. 